Obesity has been associated with several common cancer sites in epidemiologic studies. However, the human evidence for most of these associations is still equivocal despite strong supportive data in laboratory animal studies. Also, in most instances it is not clear whether obesity is related to carcinogenesis in its early or late stages. This nested case-control study will examine the relationship of young-adult obesity, middle-age obesity and weight gain between youth and middle-age to cancer risks among the mend and women included in an historical cohort (N=46,000), which will be assembled by linkage of various population-based data sets available in Hawaii. Preliminary data from an ongoing investigation of the relationship between body size and breast cancer have confirmed the feasibility of this approach, as well as the validity of the computer-assisted linkage methodology and the quality of the historically-recorded data to be used in the proposed study. Cases with histologically-confirmed cancers of the stomach (n=273), colon (n=433), rectum (n=261), lung (n=727), endometrium (n=216), cervix (n=59), ovary (n=76), prostate (n=220), bladder (n=128) and kidney (n=93) will be identified for the period 1972 to 1985 by linkage with the Hawaii Tumor Registry. Three controls randomly selected from the cancer-free cohort members will be matched on sex, race and birth-year to each cancer case. A case-control multivariate analysis will compare the subjects' relative weight as young and middle-age adults, as well as the change in body mass index between the two periods, while adjusting for some other known cancer risk factors. This study should provide useful results to clarify the role of obesity in cancer risk.